This invention relates generally to dies and, more particularly, to dies for use in forming lead wires of electrical components into a predetermined shape. Referring to FIG. 1 a double camel hump component is shown. This component must meet government Weapon Specification 6536 Revision E which requires that the minimum inside bend radius R of any bend on the formed lead shall be 1 lead diameter. Weapon Specification 6536 Rev. E (WS 6536 Rev. E) also requires that the component span width W be short enough to allow mounting of components on printed wiring boards without bending the leads inwardly from the shoulders, i.e. the components must be mounted parallel to the board and the leads must form a right angle with the board surface. A typical width W is, for example, 0.350 inches.
The current standard double camel hump component made using a Mark V lead forming machine manufactured by Technical Devices Co. does not meet the component span width required by WS 6536 Rev. E. It is known that a single camel hump component will decrease the component span width W. Prior art dies are not capable of making a single camel hump component which meets government specifications due to the unequal forces applied to the lead wires and the component. These unequal forces result in an unacceptably high percentage of deformed and/or damaged parts.
Referring to FIG. 2 a prior art die is shown. Component piece 5 having lead wires 10 restrained by clamping fingers 15 has lead wires 10 bent using right wire bending piece 20 and left wire bending piece 25. Form plates 30 and 35 act to bend lead wires 10 into the two camel humps. The forces applied to lead wires 10 in FIG. 2 are equal due to the simultaneous bending action of the wire bending pieces 20 and 25. If one of the wire camel hump form plates is removed to produce a single camel hump component it is readily apparent that unequal forces will be applied to the component causing stress which results in deformed and/or damaged components. It is an advantage of the present invention that components may be formed in a single camel hump configuration without damaging or deforming the components. Total encapsulation of the component and lead wires while forming the leads results in equal restraining forces on both sides of the component. Therefore, all stresses are external to what is encapsulated which results in correctly formed lead wires for unstressed components which meet the requirements of WS 6536 Rev. E. Other advantages include formation of a component with a span width short enough to allow mounting of components on printed wiring boards without bending the leads inwardly from the lead shoulders and a minimum inside bend radius of one lead diameter. Further, the die can be used with loose components or tape and reel components and the die will work in already existing equipment.
As those skilled in the art know, prior art dies such as that shown in FIG. 2 which utilize clamping fingers 15 introduce further possible error because the operator could put too much pressure on the clamping fingers causing excess force on the leads which in turn causes distortion. This problem is eliminated by the total encapsulation of the part in the present invention.